Here, then, we see that the propensities that are the most marked, and the most constant in every breed of domestic dogs, are not to be found in animals of the same species in their natural state, or even in their young, although subjected to the same treatment from the moment of their birth.

Notwithstanding the above-mentioned fact, we may, I think, consider the domestic dog as an animal per se; that is, that it neither owes its origin to the fox nor wolf, but is sprung from the wild dog. In giving this opinion, I am aware that some naturalists have endeavoured to trace the origin of the dog from the fox; while others, and some of the most eminent ones, are of opinion that it sprung from the wolf. I shall be able to show that the former is out of the question. The wolf, perhaps, has some claim to be considered as the parent animal, and that he is susceptible of as strong attachment as the dog is proved by the following anecdote, related by Cuvier.

He informs us, that a young wolf was brought up as a dog, became familiar with every person whom he was in the habit of seeing, and in particular, followed his master everywhere, evincing evident chagrin at his absence, obeying his voice, and showing a degree of submission scarcely differing in any respect from that of the domesticated dog. His master, being obliged to be absent for a time, presented his pet to the Ménagerie du Roi, where the animal, confined in a den, continued disconsolate, and would scarcely eat his food. At length, however, his health returned, he became attached to his keepers, and appeared to have forgotten all his former affection; when, after an absence of eighteen months, his master returned. At the first word he uttered, the wolf, who had not perceived him amongst the crowd, recognised him, and exhibited the most lively joy. On being set at liberty, the most affectionate caresses were lavished on his old master, such as the most attached dog would have shown after an absence of a few days.

A second separation was followed by similar demonstrations of sorrow, which, however, again yielded to time. Three years passed, and the wolf was living happily in company with a dog, which had been placed with him, when his master again returned, and again the long-lost but still-remembered voice was instantly replied to by the most impatient cries, which were redoubled as soon as the poor animal was set at liberty; when, rushing to his master, he threw his fore-feet on his shoulders, licking his face with the most lively joy, and menacing his keepers, who offered to remove him, and towards whom, not a moment before, he had been showing every mark of fondness.

A third separation, however, seemed to be too much for this faithful animal's temper. He became gloomy, desponding, refused his food, and for a long time his life appeared in great danger. His health at last returned, but he no longer suffered the caresses of any but his keepers, and towards strangers manifested the original savageness of his species.

Mr. Bell, in his "History of Quadrupeds," mentions a curious fact, which, I think, still more strongly proves the alliance of the dog with the wolf, and is indeed exactly similar to what is frequently done by dogs when in a state of domestication. He informs us, that he "remembers a bitch-wolf at the Zoological Gardens, which would always come to the front bars of her den to be caressed as soon as he, or any other person whom she knew, approached. When she had pups, she used to bring them in her mouth to be noticed; and so eager, in fact, was she that her little ones should share with her in the notice of her friends, that she killed all of them in succession by rubbing them against the bars of her den, as she brought them forwards to be fondled."

Other instances might be mentioned of the strong attachment felt by wolves to those who have treated them kindly, but I will now introduce some remarks on the anatomical affinities between the dog, the fox, and the wolf, which serve to prove that the dog is of a breed distinct from either of the last-mentioned animals.

It must, in fact, be always an interesting matter of inquiry respecting the descent of an animal so faithful to man, and so exclusively his associate and his friend, as the dog. Accordingly, this question has been entertained ever since Natural History took the rank of a science. But the origin of the dog is lost in antiquity. We find him occupying a place in the earliest pagan worship; his name has been given to one of the first-mentioned stars of the heavens, and his effigy may be seen in some of the most ancient works of art. Pliny was of opinion that there was no domestic animal without its unsubdued counterpart, and dogs are known to exist absolutely wild in various parts of the old and new world. The Dingo of New Holland, a magnificent animal of this kind, has been shown to be susceptible of mutual attachment in a singular degree, though none of the experiments yet made have proved that he is capable, like the domestic dog, of a similar attachment to man. The parentage of the wild dogs has been assigned to the tame species, strayed from the dominion of their masters. This, however, still remains a question, and there is reason to believe that the wild dog is just as much a native of the wilderness as the lion or tiger. If there be these doubts about an animal left for centuries in a state of nature, how can we expect to unravel the difficulties accumulated by ages of domestication? Who knows for a certainty the true prototype of the goat, the sheep, or the ox? To the unscientific reader such questions might appear idle, as having been settled from time immemorial; yet they have never been finally disposed of. The difficulty, as with the dog, may be connected with modifications of form and colour, resulting from the long-continued interference of man with the breed and habits of animals subjected to his sway.

Buffon was very eloquent in behalf of the claim of the sheep-dog to be considered as the true ancestor of all the other varieties. Mr. Hunter would award this distinction to the wolf; supposing also that the jackal is the same animal a step further advanced towards civilization, or perhaps the dog returned to its wild state. As the affinity between wolf, jackal, fox, and dog, cannot fail to attract the notice of the most superficial observer; so he may ask if they do not all really belong to one species, modified by varieties of climate, food, and education? If answered in the negative, he would want to know what constitutes a species, little thinking that this question, apparently so simple, involves one of the nicest problems in natural history. Difference of form will scarcely avail us here, for the pug, greyhound, and spaniel, are wider apart in this respect, than many dogs and the wild animals just named. It has often been said that these varieties in the dog have arisen from artificial habits and breeding through a long succession of years. This seems very like mere conjecture. Can the greyhound be trained to the pointer's scent or the spaniel to the bulldog's ferocity? But admitting the causes assigned to be adequate to the effects, then the forms would be temporary, and those of a permanent kind only would serve our purpose. Of this nature is the shape of the pupil of the eye, which may be noticed somewhat particularly, not merely to make it plain to those who have never thought on the subject, but with the hope of leading them to reflections on this wondrous inlet to half our knowledge, the more especially as the part in question may be examined by any one in his own person by the help of a looking-glass. In the front of the eye then, just behind the transparent surface, there is a sort of curtain called the iris, about the middle of which is a round hole. This is the pupil, and you will observe that it contracts in a strong light, and dilates in a weaker one, the object of which is to regulate the quantity of light admitted into the eye. Now the figure of the pupil is not the same in all animals. In the horse it is oval; in the wolf, jackal, and dog, it is round, like our own, however contracted; but in the fox, as in the cat, the pupil contracts vertically into an elongated figure, like the section of a lens, and even to a sort of slit, if the light be very strong.

This is a permanent character, not affected, as far as is at present known, by any artificial or natural circumstances to which the dog has been subjected. Naturalists, therefore, have seized upon this character as the ground for a division of animals of the dog kind, the great genus Canis of Linnæus, into two groups, the diurnal and nocturnal; not to imply that these habits necessarily belong to all the individuals composing either of these divisions, for that would be untrue, but simply that the figure of the pupils corresponds with that frequently distinguishing day-roaming animals from those that prowl only by night. It is remarkable that a more certain and serviceable specific distinction is thus afforded by a little anatomical point, than by any of the more obvious circumstances of form, size, or colour. Whether future researches into the minute structure of animals may not discover other means to assist the naturalist in distinguishing nearly allied species, is a most important subject for inquiry, which cannot be entertained here. But to encourage those who may be disposed to undertake it, I must mention the curious fact, that the group to which the camel belongs is not more certainly indicated by his grotesque and singular figure than by the form of the red particles which circulate in his blood. And here again the inherent interest of the matter will lead me to enter a little into particulars, which may engage any one who has a good microscope in a most instructive course of observations, not the least recommendation of which is, that a just and pleasing source of recreation may be thus pursued by evening parties in the drawing-room, since the slightest prick of the finger will furnish blood enough for a microscopic entertainment, and you may readily procure a little more for comparison from any animal.